Ross is perhaps the unluckiest of all the Friends in love (once claiming to have been "dumped during sex").

Carol

He divorced his first wife of eight years (although in the beginning claimed to be four years), Carol Willick, when it emerged that she was a lesbian and was having an affair with another woman. However, in a flashback episode to when he and Carol were newly dating, he gushed about how "she's on the lacrosse team and the golf team" and he enthuses that "she plays for both teams!". They still got along fairly well, however, and shared custody of their son Ben, who was born in 'The One with the Birth', one of the final episodes of the first season. Ross' age when he married Carol is, considering he states he's "26 and divorced" during the first episodes of the series, either 22 or 18. Since the latter has been referenced more (they claim to be married in 1989, when Ross was 21) it is safe to assume they both got married at around 18, during Ross' stay at college.

In an alternate reality storyline during the show ("The One That Could Have Been, Part 1"), Ross remained married to Carol, but their sex life was stagnant. He doesn't seem to realize Carol is a lesbian. When Ross suggests to Carol that they have a threesome, she not only is all for it, but has the perfect woman: Susan. Ross is forced to accept that his wife is gay, and he ends up consoling Rachel after she discovers that her fiance (Barry Farber, whom she leaves at the altar in "The Pilot") is having an affair as well.

Emily

Ross's second marriage, to his English girlfriend Emily Waltham, appeared more hopeful than his first. The wedding took place in London (in a half-demolished building, where her parents were married), where Joey and Chandler were both the best man and Monica was a bridesmaid. (Phoebe could not attend as she was too far into pregnancy, and Rachel only came at the last minute.) However, at the ceremony Ross said Rachel's name instead of Emily's which led to the complete breakdown of his relationship. Ross attempted to reconcile with Emily, but she insisted that Ross never see nor speak to Rachel ever again. Ross was unable to comply; when Emily found out that Ross had been spending time with the friends (including Rachel) she realized she could never trust Ross again, and the marriage quickly dissolved.

Rachel

Ross is perhaps most famous for his turbulent relationship with Rachel Green. Ross had harbored a crush for Rachel since their high school days, when Rachel was Monica's best friend. When Rachel moved to the city, Ross's affection returned, and after a rocky start the two finally got together in "The One with the Prom Video". The relationship ended with Ross's jealousy over Rachel's co-worker Mark. Believing them to be "on a break", he slept with Chloe (Angela Featherstone), the "cute girl from the copy place with a belly-button ring". When Rachel found out, she broke up with Ross in a famous scene in Monica's apartment, which involved Ross and Rachel arguing in Monica's living room whilst the other four Friends are trapped in Monica's bedroom, afraid of interrupting the argument. (The scene was so emotional that both David Schwimmer and Jennifer Aniston actually cried after it was shot.) The two shared an 'almost on-again, almost off-again' relationship over the years. They even got married as a result of a drinking binge in Las Vegas. This wasn't resolved until weeks later when - unable to get an annulment - they had to get a divorce, leading Ross to panic over being a triple divorcee. Later in the series, they slept together again, resulting in the birth of Ross's second child Emma. In "The Last One", Ross is encouraged by Phoebe to declare his love to Rachel before she leaves to pursue a career in Paris. His plea is successful and the two once again enter into a relationship. It is rumored that Ross and Rachel eventually got married in the Friends spinoff Joey, with Joey claiming that all his friends are married.